I have a camo one, can see through it in daylight & it is held Way off of me by the ridgeline (It's on top of the bug netting) so limited from a closet-phobia POV.
Around 5 this morning mine got too warm so I had to half uncover it. I agree that it adds at least 10 degrees, maybe as much as 20 YMMV. So more than a open tarp. A closed ended tarp can add nearly 10 degrees IMHO so,,,,,,,,
IF you sleep cold, pound for pound a "Hammock sock" or similar cover like the BBO can mean the difference between being cold all night & sleeping the night away. The lower half of my "similar to a hammock sock" is a 1X by Molly Mac. Combined they add at least 20 - 30 degrees to my comfort level.
When you have a backpack on, no matter where you are, you’re home.
PAIN is INEVITABLE. MISERY is OPTIONAL.